As a prior art of a multiple electronic control throttle body for an outboard motor, there has been Japanese Unexamined Patent Publication No. 2002-371865 filed by the applicant of the present invention.
In accordance with this structure, a plurality of intake passages provided through in a sideward direction are arranged in a vertical direction, respective throttle valve shafts are arranged in the respective intake passages transversely, and respective throttle valves opening and closing the respective intake passages are attached to the respective throttle valve shafts.
Further, a throttle body with which an adjusting screw is engaged is firmly fixed to each of the throttle valve shafts, and a worm lever provided with a worm gear on an outer periphery and a locking lever is arranged in a loosely fitting manner in each of the throttle valve shafts.
Further, the worm shaft is arranged so as to be rotatable and movable in a vertical direction, the motor is connected to an upper end of the worm shaft, and the worm gear in each of the worm levers is arranged so as to be engaged with the worm shaft.
In accordance with the structure mentioned above, when the motor is rotated, the worm shaft is rotated synchronously with the motor, and the rotation is transmitted to each of the worm levers via the worm gear. Accordingly, when the worm lever is rotated forward, each of the throttle valves opens each of the intake passages in correspondence to the rotation of the motor. On the other hand, when the worm lever is rotated backward, each of the throttle valves closes each of the intake passages also in correspondence to the rotation of the motor.
On the other hand, in the fuel injection apparatus for the outboard engine, a vapor separator provided with a high-pressure fuel pump is required. This structure is shown in Japanese Unexamined Patent Publication No. 8-312485.
In accordance with this structure, a fixed liquid level control apparatus constituted by a float, a valve seat and a float valve is arranged within a casing, and fuel supplied from a low-pressure fuel pump forms and holds in a fixed liquid level within the casing by the fixed liquid level control apparatus.
Further, the fuel within the vapor separator is sucked into the high-pressure fuel pump so as to be increased in pressure, and the fuel having the increased pressure is supplied toward the fuel injection valve.
In accordance with the conventional multiple throttle body for the outboard motor mentioned above, since the throttle valve shaft, the throttle lever and the worm lever are required for each of the intake passages, a number of parts and an assembling man-hour are increased, and it is hard to reduce a manufacturing cost.
Further, in the outboard engine, a crank shaft of the engine is generally arranged in a vertical direction with its lengthwise side on the basis of a relation with a screw which is placed in an approximately horizontal direction. Accordingly, a plurality of intake passages are arranged in the vertical direction.
Therefore, the worm shaft is arranged in the vertical direction. In the case that the motor is arranged in an upper end of the worm shaft, the motor protrudes largely to an upper side, a height is increased, and a design freedom of a cowling covering an entire outer periphery of the engine is inhibited.